diff --git a/OpenRA.Mods.RA/Player/ProductionQueue.cs b/OpenRA.Mods.RA/Player/ProductionQueue.cs
index 46fb2eb5d4..8a095f96ee 100644
--- a/OpenRA.Mods.RA/Player/ProductionQueue.cs
+++ b/OpenRA.Mods.RA/Player/ProductionQueue.cs
@@ -166,7 +166,7 @@ namespace OpenRA.Mods.RA
 			Produceable[self.World.Map.Rules.Actors[key]].Visible = false;
 		}
 
-		public void PrerequisitesItemVisable(string key)
+		public void PrerequisitesItemVisible(string key)
 		{
 			Produceable[self.World.Map.Rules.Actors[key]].Visible = true;
 		}
diff --git a/OpenRA.Mods.RA/Player/TechTree.cs b/OpenRA.Mods.RA/Player/TechTree.cs
index 131818239f..24e76c2a7a 100755
--- a/OpenRA.Mods.RA/Player/TechTree.cs
+++ b/OpenRA.Mods.RA/Player/TechTree.cs
@@ -142,7 +142,7 @@ namespace OpenRA.Mods.RA
 					watcher.PrerequisitesItemHidden(Key);
 
 				if (!nowHidden && hidden)
-					watcher.PrerequisitesItemVisable(Key);
+					watcher.PrerequisitesItemVisible(Key);
 
 				if (nowHasPrerequisites && !hasPrerequisites)
 					watcher.PrerequisitesAvailable(Key);
diff --git a/OpenRA.Mods.RA/SupportPowers/SupportPower.cs b/OpenRA.Mods.RA/SupportPowers/SupportPower.cs
index 86231f77c4..506ad62584 100755
--- a/OpenRA.Mods.RA/SupportPowers/SupportPower.cs
+++ b/OpenRA.Mods.RA/SupportPowers/SupportPower.cs
@@ -20,6 +20,7 @@ namespace OpenRA.Mods.RA
 		public readonly string LongDesc = "";
 		public readonly bool AllowMultiple = false;
 		public readonly bool OneShot = false;
+		public readonly string[] Prerequisites = {};
 
 		public readonly string BeginChargeSound = null;
 		public readonly string EndChargeSound = null;
diff --git a/OpenRA.Mods.RA/SupportPowers/SupportPowerManager.cs b/OpenRA.Mods.RA/SupportPowers/SupportPowerManager.cs
index 7d35647115..5bceff7b41 100644
--- a/OpenRA.Mods.RA/SupportPowers/SupportPowerManager.cs
+++ b/OpenRA.Mods.RA/SupportPowers/SupportPowerManager.cs
@@ -16,23 +16,25 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.RA
 {
-	public class SupportPowerManagerInfo : ITraitInfo, Requires<DeveloperModeInfo>
+	public class SupportPowerManagerInfo : ITraitInfo, Requires<DeveloperModeInfo>, Requires<TechTreeInfo>
 	{
 		public object Create(ActorInitializer init) { return new SupportPowerManager(init); }
 	}
 
-	public class SupportPowerManager : ITick, IResolveOrder
+	public class SupportPowerManager : ITick, IResolveOrder, ITechTreeElement
 	{
 		public readonly Actor self;
 		public readonly Dictionary<string, SupportPowerInstance> Powers = new Dictionary<string, SupportPowerInstance>();
 
 		public readonly DeveloperMode DevMode;
+		public readonly TechTree TechTree;
 		public readonly Lazy<RadarPings> RadarPings;
 
 		public SupportPowerManager(ActorInitializer init)
 		{
 			self = init.self;
-			DevMode = init.self.Trait<DeveloperMode>();
+			DevMode = self.Trait<DeveloperMode>();
+			TechTree = self.Trait<TechTree>();
 			RadarPings = Exts.Lazy(() => init.world.WorldActor.TraitOrDefault<RadarPings>());
 
 			init.world.ActorAdded += ActorAdded;
@@ -46,28 +48,30 @@ namespace OpenRA.Mods.RA
 
 		void ActorAdded(Actor a)
 		{
-			if (a.Owner != self.Owner || !a.HasTrait<SupportPower>())
+			if (a.Owner != self.Owner)
 				return;
 
 			foreach (var t in a.TraitsImplementing<SupportPower>())
 			{
 				var key = MakeKey(t);
 
-				if (Powers.ContainsKey(key))
+				if (!Powers.ContainsKey(key))
 				{
-					Powers[key].Instances.Add(t);
-				}
-				else
-				{
-					var si = new SupportPowerInstance(key, this)
+					Powers.Add(key, new SupportPowerInstance(key, this)
 					{
-						Instances = new List<SupportPower>() { t },
+						Instances = new List<SupportPower>(),
 						RemainingTime = t.Info.ChargeTime * 25,
 						TotalTime = t.Info.ChargeTime * 25,
-					};
+					});
 
-					Powers.Add(key, si);
+					if (t.Info.Prerequisites.Any())
+					{
+						TechTree.Add(key, t.Info.Prerequisites, 0, this);
+						TechTree.Update();
+					}
 				}
+
+				Powers[key].Instances.Add(t);
 			}
 		}
 
@@ -80,8 +84,13 @@ namespace OpenRA.Mods.RA
 			{
 				var key = MakeKey(t);
 				Powers[key].Instances.Remove(t);
+
 				if (Powers[key].Instances.Count == 0 && !Powers[key].Disabled)
+				{
 					Powers.Remove(key);
+					TechTree.Remove(key);
+					TechTree.Update();
+				}
 			}
 		}
 
@@ -114,6 +123,28 @@ namespace OpenRA.Mods.RA
 			return a.TraitsImplementing<SupportPower>()
 				.Select(t => Powers[MakeKey(t)]);
 		}
+
+		public void PrerequisitesAvailable(string key)
+		{
+			SupportPowerInstance sp;
+			if (!Powers.TryGetValue(key, out sp))
+				return;
+
+			sp.Disabled = false;
+		}
+
+		public void PrerequisitesUnavailable(string key)
+		{
+			SupportPowerInstance sp;
+			if (!Powers.TryGetValue(key, out sp))
+				return;
+
+			sp.Disabled = true;
+			sp.RemainingTime = sp.TotalTime;
+		}
+
+		public void PrerequisitesItemHidden(string key) { }
+		public void PrerequisitesItemVisible(string key) { }
 	}
 
 	public class SupportPowerInstance
@@ -125,7 +156,7 @@ namespace OpenRA.Mods.RA
 		public int RemainingTime;
 		public int TotalTime;
 		public bool Active { get; private set; }
-		public bool Disabled { get; private set; }
+		public bool Disabled { get; set; }
 
 		public SupportPowerInfo Info { get { return Instances.Select(i => i.Info).FirstOrDefault(); } }
 		public bool Ready { get { return Active && RemainingTime == 0; } }
diff --git a/OpenRA.Mods.RA/TraitsInterfaces.cs b/OpenRA.Mods.RA/TraitsInterfaces.cs
index 63c088db17..0e166c14ff 100755
--- a/OpenRA.Mods.RA/TraitsInterfaces.cs
+++ b/OpenRA.Mods.RA/TraitsInterfaces.cs
@@ -33,7 +33,7 @@ namespace OpenRA.Mods.RA
 		void PrerequisitesAvailable(string key);
 		void PrerequisitesUnavailable(string key);
 		void PrerequisitesItemHidden(string key);
-		void PrerequisitesItemVisable(string key);
+		void PrerequisitesItemVisible(string key);
 	}
 
 	public interface ITechTreePrerequisite
diff --git a/mods/ra/rules/structures.yaml b/mods/ra/rules/structures.yaml
index f1d7b2fe18..db6f99be28 100644
--- a/mods/ra/rules/structures.yaml
+++ b/mods/ra/rules/structures.yaml
@@ -985,7 +985,6 @@ AFLD:
 		ChargeTime: 360
 		Description: Paratroopers
 		LongDesc: A Badger drops a squad of infantry\nanywhere on the map.
-		Prerequisites: AFLD
 		DropItems: E1,E1,E1,E3,E3
 		SelectTargetSound: slcttgt1.aud
 	ProductionBar: